28 THE SCIENTIFIC FEEDING OF ANIMALS 



as high as 29 per cent free acid (two-thirds lactic and one-third acetic 

 acid and under unfavorable conditions quantities of butyric acid) (esti- 

 mates for the dry matter — Morgen). 



In good silos silage will keep almost indefinitely (one year), but it 

 quickly spoils when exposed to the air. The process of silage prepara- 

 tion causes a loss of about 20 to 35 per cent of the dry matter. The crude 

 protein suffers most, being converted into ammonia and nitrogen- free 

 extract with formation of organic acids. On account of the great losses 

 inevitable in the preparation of silage, this method should not be practiced 

 when other means of preservation are possible and successful. 



The usual method of silage preparation is attended with the develop- 

 ment of great numbers of different species of microorganisms (bacteria, 

 mold and yeast fungi) (Henneberg) which cause desirable as well as un- 

 desirable fermentations and decompositions. Henneberg recommends 

 inoculation with pure cultures of desirable species of bacteria in order to 

 control the character of the product. 



Inoculation gives the best results with feeding stuffs comparatively free 

 from bacteria, like steamed or sterilized shredded beets, potatoes, etc. 

 Whether inoculation would be of any advantage for feeding stuffs com- 

 paratively rich in a bacterial flora, like grass, beets and beet tops, etc., is 

 still an unsettled question. 



II. The Preparation of Feeding Stuffs 



This subject will be discussed under the following heads: 



1. The reduction of coarse material into fine particles. 



2. Moistening and soaking. 



3. Cooking, scalding and steaming. 



4. Roasting. 



5. Leaching. 



6. Fermenting. 



7. The conversion of indigestible into digestible matter. 



8. Predigestion. 



9. Baking. 



1. The reduction of coarse feed particles to smaller size (especially 

 the roughages) saves energy by assisting or supplementing mastication. 

 The usual method consists of cutting or chaffing. Chaffed straw for 

 cattle is usually cut about one or one and one-half inches in length ; for 

 horses about four-fifths of an inch ; for sheep one-half to one inch. Green 

 forage or hay is usually cut a little longer. 



Digestibility is not affected by this process, nor by grinding. It only 

 aids mastication, which, in the case of straw, is not even always desirable. 



Root crops (potatoes, beets, etc.) are cut or chopped for hygienic rea- 

 sons (to prevent choking) and to facilitate mixing with less palatable 

 feeding stuffs, or they may be cooked and crushed. Chopped root crops 

 are subject to spoiling and should therefore be fed the same day they 

 are prepared. 



